I had a similar issue and fixed it this way. Caveat: I have an unusual router at home.
https://en.wikipedia.org/wiki/Hairpinning
applicable mikrotik configuration (x.x.x.x masks public IP)
Code:
1 ;;; hairpin
chain=dstnat action=dst-nat to-addresses=192.168.88.254 src-address=192.168.88.0/24
dst-address=x.x.x.x log=no log-prefix=""
2 chain=srcnat action=masquerade src-address=192.168.88.0/24 dst-address=192.168.88.254 log=no
log-prefix=""
I haven't had a login server running in a while, but I'll go ahead and get it set up and disable the hairpin to see if I'm back to the same problem as before. Which was: "HALP! I can't connect to server on same machine through public login. I disconnect after char select/create, but can log in locally with no issue." or something, IIRC.